Our vacuum pressure impregnation (VPI) process involves pre-baking the workpiece to remove moisture, then cooling it down before placing it in a vacuum vessel to evacuate air and volatile substances from inside the bare coil. Under vacuum, the impregnating varnish or resin is drawn in by gravity and capillary action. After the vacuum stage, dried compressed air or an inert gas is applied under pressure to force the varnish to rapidly penetrate and fill the deeper layers of the insulation structure.

This VPI technology is particularly suitable for large high-voltage coils, multilayer uniformly wound yoke coils, large windings with stringent specifications, and other demanding high-voltage coil applications. It effectively slows down insulation deterioration and reduces cracking.

• High-Efficiency Impregnation with Complete Penetration
  Leveraging the combined action of vacuum and pressure, the VPI system rapidly removes air and moisture from pores and gaps in the workpiece. The impregnation medium such as insulating varnish or resin penetrates deeply into fine structures, eliminating air bubbles and dry spots common in traditional methods. This significantly enhances insulation, sealing performance, and mechanical strength.
• Precision Temperature Control for Diverse Materials
  Equipped with an intelligent temperature control system, the VPI chamber can be precisely adjusted to match the properties of various impregnation media (e.g., viscosity, curing temperature). This ensures optimal results for a wide range of components, including motors, transformers, and electronic devices, meeting diverse production needs.
• Automated Operation for Reduced Labor Costs
  An integrated PLC control system allows operators to preset process parameters such as vacuum level, pressure, and dwell time. With one-button start, the entire cycle runs automatically, minimizing manual intervention, reducing human error, and improving production efficiency.
• Safety and Stability for Reliable Production
  Constructed from high-strength alloy with excellent pressure and corrosion resistance, the VPI vessel is equipped with multiple safety mechanisms including overpressure alarms, leakage protection, and temperature overload safeguards to ensure stable, hazard-free operation.
• Energy-Efficient and Environmentally Friendly
  Optimized vacuum and heating systems reduce energy consumption, while superior sealing minimizes impregnation medium loss. A built-in waste recovery system meets environmental standards and supports cost reduction and efficiency improvement.